v1.0.0 - GitHub Action

First release of the sentinel-scan-cli GitHub Action.

Wraps sentinel-scan mcp for CI: scans an MCP tool manifest for
prompt-injection, excessive-agency, and other OWASP LLM Top 10 risks,
then fails the build on a configurable severity threshold.

Usage:

- uses: Ventrova/sentinel-scan-cli@v1
  with:
    manifest: mcp.json
    fail-on-severity: high
    format: sarif
    output: sentinel-scan-results.sarif

Inputs: manifest, fail-on-severity (high/medium/low/none), format
(sarif/markdown/json), output. Outputs: results-file, finding-count.

No PyPI/npm publish dependency - the action installs the Python package
straight from this repo's own checkout at ${{ github.action_path }}.

The v1 tag tracks the latest v1.x.x release, per GitHub's recommended
Action versioning convention.